1. Field of the Invention
The present invention relates to a centrifuge for a semiconductor wafer and a centrifuging method carried out therewith.
2. The Prior Art
Centrifuges for semiconductor wafers are known. For example, EP-434,307 A2 describes a centrifuge which is used for drying a semiconductor wafer.
When using such a centrifuge, there is a risk of the semiconductor wafer being contaminated during centrifuging, for example by particles which emanate from the centrifuge. Rebounding of drops which have been centrifuged off onto dry points on the semiconductor wafer may also lead to recontamination.
It is an object of the present invention to provide an improved centrifuge in which this risk of recontamination is substantially eliminated.
A further object of the present invention is a method for centrifuging a semiconductor wafer, wherein the semiconductor wafer is centrifuged in a laminar gas flow.
The above objects are achieved according to the present invention by providing a centrifuge for a semiconductor wafer, having a centrifuge plate for holding the semiconductor wafer, having a drive for rotating the centrifuge plate, and having a device for supplying a medium to a front side and a rear side of the semiconductor wafer, which has a housing which separates a centrifuging area and the semiconductor wafer from the environment, and a device for generating a laminar gas flow in the housing.
The present invention ensures that the contamination from particles or other undesirable substances is minimal when the semiconductor wafer is being centrifuged. The invention may be used to dry the semiconductor wafer, and it may be used to treat it with a liquid, for example to rinse the semiconductor wafer with water. Particles are carried out of the housing of the centrifuge by a laminar gas flow. Liquids which are centrifuged radially off the semiconductor wafer are discharged downward along a sloping surface. Substances which were released from the liquid or particles which the liquid picked up are thus prevented from recontaminating the semiconductor wafer.